CPoolRecord Class Reference

A description of a byte-code object referenced by a constant. More...

#include <cpool.hh>

Public Types
enum	{   primitive =0, string_literal =1, class_reference =2, pointer_method =3,   pointer_field =4, array_length =5, instance_of =6, check_cast =7 }
	Generic constant pool tag types. More...
enum	{ has_thisptr = 0x1, is_constructor = 0x2, is_destructor = 0x4 }

Public Member Functions
	CPoolRecord (void)
	Construct an empty record.
	~CPoolRecord (void)
	Destructor.
uint4	getTag (void) const
	Get the type of record.
const string &	getToken (void) const
	Get name of method or data-type.
const uint1 *	getByteData (void) const
	Get pointer to string literal data.
int4	getByteDataLength (void) const
	Number of bytes of string literal data.
Datatype *	getType (void) const
	Get the data-type associated with this.
uintb	getValue (void) const
	Get the constant value associated with this.
bool	hasThisPointer (void) const
	Is object a method with a this pointer.
bool	isConstructor (void) const
	Is object a constructor method.
bool	isDestructor (void) const
	Is object a destructor method.
void	saveXml (ostream &s) const
	Save object to an XML stream. More...
void	restoreXml (const Element *el, TypeFactory &typegrp)
	Restore object from XML stream. More...

Private Attributes
uint4	tag
	Descriptor of type of the object.
uint4	flags
	Additional boolean properties on the record.
string	token
	Name or token associated with the object.
uintb	value
	Constant value of the object (if known)
Datatype *	type
	Data-type associated with the object.
uint1 *	byteData
	For string literals, the raw byte data of the string.
int4	byteDataLen
	The number of bytes in the data for a string literal.

Friends
class	ConstantPool

Detailed Description

A description of a byte-code object referenced by a constant.

Byte-code languages can make use of objects that the system knows about but which aren't fully embedded in the encoding of instructions that use them. Instead the instruction refers to the object via a special encoded reference. This class describes one object described by such a reference. In order to provide a concrete interpretation of the instruction (i.e. a p-code translation), these objects generally resolve to some sort of constant value (hence the term constant pool). The type of constant goes to the formal CPoolRecord tag field which can be a:

• Primitive value (integer, floating-point)
• String literal (pointer to)
• Class method (pointer to)
• Class field (offset of)
• Array length
• Data-type (pointer to a descriptor)

For decompilation, knowing the actual constant a byte-code interpreter would need is secondary to knowing what object is being referenced. So the CPoolRecord can hold a constant value, but generally it provides a data-type associated with the object and a symbol name or other string token naming the object.

Member Enumeration Documentation

anonymous enum

anonymous enum

Generic constant pool tag types.

Enumerator
primitive	Constant value of data-type type, cpool operator can be eliminated.
string_literal	Constant reference to string (passed back as byteData)
class_reference	Reference to (system level) class object, token holds class name.
pointer_method	Pointer to a method, name in token, signature in type.
pointer_field	Pointer to a field, name in token, data-type in type.
array_length	Integer length, token is language specific indicator, type is integral data-type.
instance_of	Boolean value, token is language specific indicator, type is boolean data-type.
check_cast	Pointer to object, new name in token, new data-type in type.

anonymous enum

anonymous enum

Enumerator
has_thisptr	Referenced method has a this pointer.
is_constructor	Referenced method is a constructor.
is_destructor	Referenced method is a destructor.

Member Function Documentation

restoreXml()

void CPoolRecord::restoreXml	(	const Element *	el,
		TypeFactory &	typegrp
	)

Restore object from XML stream.

Initialize this CPoolRecord instance from a <cpoolrec> tag.

Parameters

el	is the <cpoolrec> element
typegrp	is the TypeFactory used to resolve data-types

References array_length, byteData, byteDataLen, check_cast, class_reference, flags, has_thisptr, instance_of, is_constructor, is_destructor, isConstructor(), isDestructor(), pointer_field, pointer_method, primitive, TypeFactory::restoreXmlType(), TypeFactory::restoreXmlTypeWithCodeFlags(), string_literal, tag, token, type, and value.

Referenced by ConstantPoolInternal::restoreXml(), and ConstantPool::restoreXmlRecord().

saveXml()

void CPoolRecord::saveXml

(

ostream &

s

)

const

Save object to an XML stream.

Save the constant pool object description as a <cpoolrec> tag.

Parameters

s	is the output stream

References array_length, byteData, byteDataLen, check_cast, class_reference, hasThisPointer(), instance_of, isConstructor(), isDestructor(), pointer_field, pointer_method, primitive, Datatype::saveXml(), string_literal, tag, token, type, and value.

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The documentation for this class was generated from the following files:

• cpool.hh
• cpool.cc